Bio 3.1

What does the liver do?

What does the liver do?

processes blood plasma by storing and detoxifying molecules

Hepatocytes

processing molecules in blood, make blood proteins for clotting

Kupffer cells

recycle hemoglobin from RBCs digested in the spleen. Bi-product is bilirubin, which is then added to bile

Stellate(lto) cells

store vitamin, co-factors and fat

What cell types signal hepatocytes to exit G0 and enter the cell cycle if the liver needs to regenerate

Stellate and Kupffer cells

Nephrons

main processing unit of the kidney

what are the cortex and medulla of the kidney composed of?

millions of nephrons

Urinary system- Step:1- Filtration

the process of transferring the liquid plasma of the blood from a blood vessel to a nephron of the kidney

____ blood pressure in afferent arterioles push small molecules across porus capillary bed cell layer

high

Urinary system- Step: 2- reabsorption

the plasma returns from the nephron to the blood vessels via the peritubular capillaries with only “good molecules”

Urinary system- Step: 3- secretion

any remaining substances, after being reabsorbed that are not needed in the blood are secreted back into the nephron to be eliminated

Urinary system- Step: 4 - excretion

removal of blood waste(urine) from the nephron to the ureters

Kidney Stones

crystals formed from urine made of calcium, phosphorus, uric acid and protein, may block ureters and cause urine to back up, destroying the nephrons

Urinary tract infections

bacterial infection, if in dysbiosis invaders can colonize and move up the urinary tract

Hypertension

High blood pressure, creates higher BP in glomeruli and can damage them if persistent

Type 2 diabetes

causes 50% of kidney failure, when blood sugar too high concentration is too high, damages nephrons

What is one way to treat kidney failure

dialysis

Central nervous system

involves brain and spinal cord, that receives processes and transfers information

Peripheral nervous system

involves nerves outside CNS, that carries information towards and away from the CNS

What percentage of cells in the nervous system are signal conducting neuron cells.

20% the rest are support cells

Neuroglia

support neurons, multiple kinds with many functions

what is the cellular basis of communication in the nervous system

neurons

action potential

sudden reversal of membrane voltage

action potential order

(1) stimulus occurs—> (2) Na+ gates open—>(3) Na+ moves into cell

What must the stimulus depolarize the membrane to for the Na+ channel to open

-55mV

what does the closes/inactive state of the Na+ channel make sure the action potential does

it makes sure the action potential doesn’t travel backwards

any stimulus strong enough to overcome the ___ will cause an action potential to fire

threshold

what makes signals different?

the frequency of actin potentials and the speed that the action potential travels down the axon at

myelin sheath

insulates the axon, saves the neuron energy, and speeds up the transmission of impulses

saltatory conduction

leaping pattern of action potential conduction

Multiple sclerosis(MS)

progressive damage to myelin sheaths in the brain and spinal cord, involves weakness, visual impairment and incontinence

Amyotrophic lateral sclerosis(ALS)

progressive damage to myelin sheaths in motor area of spinal cord, progressive weakening and wasting of skeletal muscle

synapse

specialized junction where the axon of a neuron communicates with another cell

where are neurotransmitters released

at the synapse

3 actions of receiving a cell

action potential, terminate signal or chemical response

response in postsynaptic cells depend on

how many neurons are forming synapses with it and whether the neurons forming synapses with it are excitatory or inhibitory

Convergence

occurs when one neuron receives input from many others

divergence

occurs when one neuron sends action potentials to multiple other neurons